Charles bender



`in the currents of the rivers.

, @uiten gratta atwt @fitta CHARLES BENDER, OF IIESSE DARMSTA T,GERMANY.

.Batters Patent lo. 76,041, dated lmc/L 3l, 1868.

IMPROVED WIRE-TRUSS BRIDGE.

TO ALI.'- WHOM IT MAY CONCERN:

Be it known that I, CHARLES BEND'ER, citizen of the Grand Duchy ofIIesse Darmstadt, inGermany, nowresident of the city ofNew York, in thecounty of New York, in the State of New York, have invented a newConstruction of a Wire-Truss Bridge; and I do hereby declare Vthat thefollowing is a-full and exact description ofthe same. l

The nature of my bridge-consists in the application of wire cables fortruss-bridges, to gain the advantages of the cheapncss,homogeneousness,-and strength of wire, as well as Vto secure that cheapmethod of putting up the bridges, as used for suspension-bridges, whichis dispensing with expensive pile-driving and scaffold-work To gain allsaid advantages in the cheapest and least complicated manner, I divideeach of the lower chords or cables of the bridge in three pieces, oneunbroken main cable and two smaller'side cables, the latter consist' ingof as many piecesl as there are'panclsf; further, 'I constructadjustable joints to connect the main and side cables with the uprightsand diagonals; and lastly, I apply a suitable saddle io support theforces acting in the cables, and to connect the upper aud'lower chordsin the very simplest way.

My bridge consists of a straight or curved upperchord of wood, ironcrsteel; of a bottom chord, made of iron wire, in form of a curve; ofvertical posts, and diagonal ties.

My bottom chord is constructed in such a way that'the strains in all thecross-sections are equal when'the `bridge is uniformly loaded; thegreatest savings of material are consequently made possible, the.cross-sections being, according to the nature of wire, the same.

The lower chord, if no tl'unifortnly loaded, shows' diil'erent'strainsin its'diii'erent points. The greatest dierf' ence of the strains isobserved when the heaviest possible load is brought on one side of thebridge, the other half of the same being unloaded. In these cases thediagonale are-exerted in their maximum, and their strains are necessaryto restore the equilibrium at each knot of the lowcrvchord. To transferthesefstrains to the lower chordfii separate such a part of its wholecross-scction as to stand the greatest difference ofthe cable strains. I

.divide -the separated amount of the lower chord in two ropes of equalcross-section, each of those ropes consisting `of as many single cablesas there are panels. Each of these cables is provided with coaches onboth ends, by

whicharrangemcnt the connection with uprights and diagonale is madepossible. Hereby thccross-section of the lower chord is not enlarged,the sum of the cross-sections of all three cables being exactly the sameas is necessary to stand the highest possible strain by loading thewhole bridge.

If these smaller cables or side cables, calculated accordingtto theconsiderations above mentioned, might not he separated, it would berequired to stiffentlie bridge by another separate truss, so as totransfer perfectly the weights from the points of' loading to thesupport-s of thc bridger I Y By applying the diilerent short cables, itis possible to connect the lower chord with the diagonals; anothermethod of connecting the latter, as by friction, Ste., not being Asecureenough for the use of bridges.

By the unbroken main cable, the advantage is secured of putting up thebridge in that manner used on suspension-bridges, dispensing withpile-driving and scafoldwvork in the current of the river.. I lay themiddle lines lof main and side cables in the same' horizontalcylindrical surface, and place the main cable between the side cables.By this arrangement, I facilitate the calculation, and avoid dic'ultiesarising from unequal expansion in the case that the curves of the cablesmight not be of similar form.

Tof-asten the pieces of side cables, as well as the diagonals andvertical posts, to the main cable, and to correct the position of thelatter, I have invented castings, the construction of which I willproceed to describe.: They consist of two iron plates, C, between whichruns the main cable. Erich of these plates is provided with four pegstwoto fasten the side cables, and two to fasten thc diagonals.

At the lower part of the inside, each plate is provided with two ears,through which pass iron bolts E. At the upper ends of thc inside, eachplate is provided with several teeth, Fitting exactly in respectiveholes of the covering-plate which serves to fasten the vertical posts.

Pieces of wrought iron', bent according to the shape of the cable, andVprovided with screw-bolts on both ends, as shown by Figures l, 2, E,serve to changeA and correct thepositionv of the cable, and byicreatingfriction, help tojoin the whole casting with the cnible. Two o'ftheseiron pieces :1re banging on the cable, .1nd vthe deseendinfr bolts :1remissin# thronfvh the ears above mentioned fastened b nuts and thusreventimr the risiui1 D D n 1 1 n l D of the cable. 'lwo other ironpieces of this kind 'embrace the cble from below.- Their fourscrew-bolts ure passing through four 1n'oles of the covering-pluto, undare fastened by nuts.' These bolts prevent u slipping (lown of thecable. Thin wedges of iron, bentaround tbe cable, ure applied beneuththese bolts to secure their vertid Cnl position, as shown by figs. 1, 2,m m. vWhere bottom und upper chords join,- a casting has been usefl inform i of :L saddle, offering to tbe cable a large, broad bed, :is showninFigures 6, 7.

According to the nature of the valley or the river, across which thebridge is to be built, the Hoor may be laid on the upper chord orsuspended ontbe cable by iron rods. I

Wbut'I Claim :1s my invention, :mil desire to secure by LettersPatent,is the following: 1. I claim uubottom chord, consisting ofun'unbroken main cable and side cables, the latterconsisting of asina-ny pieces as there are panels, substantially :is and for the purposespecified.

2. I claim the joints of the'bottorn chord, consisting of two si'deplates and a covering-plnte, as shown in figs. 1, Z, 3, LL, 5, theseveral parts being construetednnd userl as und'for the purpose hereinspecified.

3. I claim the saddle joining, the bottom und upper chords, inconnection with bottom chords of truss-bridges constructed of wirecables, substantially as set forth. i

New York, November 3, 1867.

CHARLES BENDER.

Witnesses:

CHARLES Fnnzrsn, Guo. W. SACKETT.

